Compressed air coal breaker



April 1, 1952 E.' c. FlLs'rRUP 2,591,529

COMPRESSED AIR com; BREAKER Filed March so, y1951 2 SHEETS- SHEET 1 Arron/iks- E.' c. FlLsTRUP colvfpRxirssED AIR COAL BREAKER April l, 1952 2 SHEETS-SHEET 2 Filed March 50, 1951 smsms .seswssss IN VEN TOR. www C /q/sez/D Patented Apr. 1, 1952 UNITED STATES 'rrr 2,591,529 CCMPRESSED Ain COAL 'Bit-nanna VEdward C. Filstrup, St. J oseph,Michaassignorjto Armstrong Coalbreak Company, "Benton Harbor, Mich., a corporation of Michigan Appi'ietionriareh so, 1951, siainofzissso l1'1 claims. (c1. iceesi This'i'nvention relates to improvements in ecmpressd air coalbreakers.

CompressedV fair coalbreakers are commonly used for breaking down coal in a mine in place of the use of blasting powder. The laws of several States prohibit the Vuse ofvblasting powder to break down or shoot coal onshift, that is, `while the men are working in the mine. Several States do, However, permit the shooting of coal by the use of compressed air devices. The ability to shoot coal on Vshift is a vsubstantial economic advantage to a mine operator. The principal advantage and safety factor of a compressed air coalbreaker, by reason of which it has use on shift, is that it obviates the hazard of explosion which occurs inconnection with the1 use of blasting powder, or inY connection with the use of com'- pressed `gas deviceslof the character which utilize aheating element to expand a gas to a blasting pressure.

The V'successful use of Aa compressed air coalbreaker is dependent upon the ability to charge a container with a large quantity of air at a very high pressure, for instance, to a pressure in the frange of from 7,0()0 Yto 12,000 pounds-per square ineh, and the ability, when the desired pressure is reached, to release the same instantaneously A`from the container. The valve mechanism is of primary importance.H 'I he valve must be of `a character which will effectively seal the container during theV time that it isbeingV charged and which will operate in a very short period of time to fully and completely exhaust the charge. v

1 have found that the use of a sleevev type of valve to close a circumferential series-of ports until the force within the chamber is 'sufficient to cause shearing of a control member is very effec'tive. Such sleeve valves, however, require the use of sealing members, suchas annular resilient seals, mounted in circumferential grooves positione'd at opposite sides of the circumferential series of discharge orifices. The valve normally spansthepcircumferential series of holes and the two annular resilient sealing means, and thus holdsthe desired pressure. In this connection the annular resilient sealing members employed are of the type commonly known in the art as O- rings and have the characteristic of deforming incident to the application of pressure so that the amount of pressure exerted is effective to create the seal, andthe greater the pressure the greater the'sealing action o f the device. Y

. To opoosuoh ovolvoihowovor, .it is ,necessary that the sleeve valve disengage one of the annular resilient sealing members as fit passes to a position opening `the discharge ports located between the two annular resilient 'sealing members. Wl'ienthis y"occurs the high gas pressure existing within the chambercauses the `sealing member disengagedby the sleeve to pop out of lits seating groove. It isinecessary, therefore, in an operativ'e device,xif the 'repeated replacement ofV one annular resilient 'sealingmemberis to be avoided, that meansbe provided to protect the sealing memberas Ythe 'same `is disengaged bythe valve. This invention V'relates principally to vnovel mechanical means for protecting this resilient sealing member.

It has previously been proposed to employel follower ring having a 'dferential area atthe two opposite ends' thereof and so sealed 'that `a predominating force responsive to the pressure in the chamber causes movementof the follower vinthe saniedirection as the sleeve moves toward open position.. Devices yof this Character aresornewhat complicated in construction, however, by reason of the fact that a number of annular 'resilient sealsl are required for the f cllowermember as weiia'srr the neet? valve. alsa-a anaes- Sary` t,o Veetffdio .follow .lSlooro to otmosohoro- Such a construction entails lsubstantial manufactufngllsfm Y It is the primary object ofthis linventiontoprovide a deviceyofl this charaeterwith va protective follower operateimoohanioally, so esto enable simpliflction ofthe constructionmand at the samel timefsecure 'ain assured and positive operation of Vtlietleviee. at all times.

A futhi- Object lf PdVefa olbl'rekakil' having 'a sleeve 'valveY cooperating with. annular resilient sealing means'to effectively seal an outlet port and chara'cteridbya follower mecha'ni cally coupled to the sleeve valve to movefwith said valve as the opening movement of thesle've occurs'said follower being uncoupledfromnsaid volveefioi iigrooollo .Feo Slolroootioeros? tion and before it assumesa position which would miete-tomb opoliofgfolit @rolia u th 'r objec s will be apparent from the followme ,Soooilioation- 1.11 ,tho drawings? Fi'g- .1., is. a. .fragmenten lositudnal axial. sootonel View of. ooooineooliioot ofA my `inv,ontlop- Fie- 2- iso fragmeotaryaxiol longitudinal S o,- tional view illustratingrthe samel construeren shownv in Fig. 1 with the parts shown in open position.

Fig. 3 is 3 tional view illustrating another embodiment of my invention.

Fig. 4 is a fragmentary longitudinal axial sectional view illustrating the valve of Fig. 3 in open position.

Fig. 5 is a longitudinal axial sectional view of the head or discharge end of a coalbreaker of a third embodiment.

Fig. 6 is a fragmentary longitudinal axial sectional view illustrating the Valve of the Fig. 5 embodiment in open position.

Referring to the drawings, and particularly to Figs. 1 and 2, which illustrate one embodiment of the invention, the numeral IU designates a tubular body which may be of any desired size and usually has an external diameter in the range of from two to three inches and a length in the range of from four feet to ten feet or more. At one end the tube is connected with an inlet (not shown) associated with a compressor (not shown) or other source of compressed air, by means of which the device may be charged. At the end opposite the intake the device is provided with an adapter tube or sleeve I2, here illustrated as externally screw-threaded at I4 to the end of the tubular body I0. An annular resilient sealing member I8 serves to seal the joint between the tube I8 and the adapter I2. The adapter I2 serves as a means to connect a discharge tube I8 to the end of the tubular body I8, and for this purpose the adapter has a screwthreaded connection at 28 at its exterior with an internal screw-threaded bore portion of the outlet sleeve I8. A resilient annular sealing member 22 serves to effectively seal the joint between the adapter I2 and the tube I8.

Intermediate its length and spaced longitudinally from the adapter I2, the outlet tube I8 is provided with a circumferential series of spaced radial discharge outlets or ports 24. A circumferential groove 26 is formed in the interior of the outlet tube I8 between the outlet ports 24 and the adapter I2, and this groove 26 receives an annular resilient sealing member 28 which preferably will be in the nature of an O-ring. A second circumferential groove 30 is formed adjacent to the circumferential series of outlet ports 24 between said ports and the outer end of the outlet tube I8. This groove 38 mounts an annular sealing member 32.

A cup-shaped head 34 has an external screw thread which has a screw-threaded connection 3B at the outer end of the outlet tube I8. An annular resilient seal 38 seals the joint between the parts I8 and 34. The cup-shaped member 34 has a reduced central bore portion 48 adjacent its outer end and the interior of the part 34 is stepped at 42 inwardly of the part 40. An insert, plate or disk 44 having a bore substantially equal to the bore part 40 spans the open end of the bore portion 42, thus defining a circumferential groove within which are received annular resilient sealing members 45. The cup-shaped member 34 has a cylindrical projection 48 at its outer end which is apertured at 50 for purposes to be described, the` portion 48 being internally screw-threaded. An end cap or plug 52 is screw-threaded in the part 48 and has a cylindrical insert 54 projecting from its inner end. The parts 52 and 54 have a bore 56 therein coaxial with and of substantially the same size as the bore 40 of the cup-shaped part 34. The part 54 defines a punch die carried by the plug 52 and is adapted to bear against a shear member, such as a pin 58, to lock the member 58 in place against 4 an aperture bearing disk in the normal po-v sition of the parts as illustrated in Fig. 1.

A sleeve valve member 62 fits slidably within the bore of the outlet tube portion I8 and is of such length that it is adapted to span the discharge ports 24 and to engage the two annular resilient sealing members 28 and 32 in its normal operative sealing position illustrated in Fig. l. The resilient sealing member has a spider 84 at one end thereof preferably provided with a plurality of apertures 56 and serving to mount an elongated plunger member 88 which extends through the bore of the disk 44, through the annular resilient sealing members 46 and through the reduced bore 48 to bear at its end against the shear pin 58. A coil spring 'I8 encircles the plunger 88, bearing at one end against the disk 44 and at its opposite end against a shoulder 'I2 formed on the stem adjacent to the apertured spider 84. A nut 'I4 may form the means for anchoring the plunger 58 to the sleeve valve 62.

The interior bore of the outlet tube I8 at the part adjacent to the adapter I2 is of a larger diameter than at the part within which the groove 25 receiving the annular sealing member 28 is formed, and a shoulder 78 is therefore provided within the outlet tube I8 between the two parts of different diameter. A follower sleeve 18 has a sliding flt in the small bore portion of the outlet tube I8 within which the circumferential groove 28 is formed. This sleeve 'I8 has an annular enlarged end portion 80 which is positioned in the large diameter portion of the outlet tube I8 to the left of the shoulder 18. The parts 'I8, 88 have a sliding t within the outlet tube I8, which t is not gas-tight so that compressed air may leak or pass around the follower sleeve 'I8 and through the clearance between the same and the outlet tube I8. Thus it will be apparent that while the follower tube 'I8 is stepped, the effective areas at both ends thereof are equal and the tube is balanced insofar as forces exerted by air pressure are concerned. The parts areY so constructed and arranged that when the valve is sealed and the follower sleeve 'I8 bears thereagainst, the parts I5 and 88 will be spaced apart as seen in Fig. l. n A space is provided between the follower 73 and the adapter I2, and a coil spring 82 is positioned within that space. the same being compressed and tending normally to move the follower sleeve 'I8 to the right.

In the operation of the device, as air pressure is built up in the tube I0, the same is resisted by the shear member 58. This pressure acts upon the area of the plunger, that is, the effective area of the port or opening 4Q, and, when the value of the for-ce as determined by the product of the area ofthe plunger times the air pressure Within the chamber, plus or minus the forces of springs 18 and 82, is sufficient to shear the pin 58, the sleeve'valve 82 will be moved toward the right to the position illustrated in Fig. 2 clearing the ports 24 and permitting the charge of air therein to be exhausted. As movement of the plunger 68 occurs, the spring 82 expands, forcing the protective follower 'I8 toward the right and maintaining the forward or right-hand end of the follower in contact with the left-hand end of the sleeve valve 62. When the enlargement 88 of the follower engages the shoulder 'I6 of the outlet tube I8, the movement of the follower is stopped and this will occur when the follower 'I8 has entered the protective sealing ring 28 so as to close or span its seating groove 28 and thus confine the ring 28 during the appli-cation of the air pressure thereto.

The point at which the parts 76 and Si) engage is so positioned that the forward or right-hand end of the follower sleeve will be positioned clear of or spaced from the outlet ports -24 so that it will not interfere with opening of the valve.

After the charge of high pressure air has been exhausted through the outlet ports 24 and the air pressure within the coalbreaker cartridge has been reduced to a value which can be overcome by the mechanical force exerted by the spring 70, the spring 'lil will expand to return the sleeve valve 62 to its position illustrated in Fig. l. For this purpose it`is preferred that the force exerted by the spring 'l shall be greater than the force exerted by the spring 82 so that the expansion of the spring 'lll will again place the spring 82 in compression. This arrangement is not necessary, however, as it will be apparent that the opening 50 within which the shear member 5d is positioned may be elongated and the play of the follower sleeve l may be so limited that the member 58 can be inserted in place even though the spring 'lll has been unable to restore the sleeve valve 52 to its fully closed position. In such case it will be apparent that the insertion of a new shear member 58 in place of the one which had been used for the last shot, followed by the screw threading of the plug 52 to cause the member 58 to be brought against the seating plate 66, will cause bodily movement of the plunger E8, the sleeve valve 62 and the follower i8 toward the left to the position illustrated in Fig. 1 with the result that the spring 82 is compressed. It will be apparent, therefore, that the only operation that is required to condition the coal-breaking device after each operation thereof is the insertion of a shear member 58 and the seating of that shear pin to insure the closing of the valve 62. It will also be apparent that the spring S2 effects a mechanical coupling between the follower i8 and the sleeve valve 62 through the permitted stroke of the follower to a position engaging and protecting the sealing ring 28.

The embodiment of the invention illustrated in Figs. 3 and 4 utilizes a mechanical latch as the coupling means between the sleeve valve and the follower member. Except for this mechanical latch, the parts are the same as those illustrated in Figs. l and 2, and parts in Figs. '3 and 4 which are similar to parts in Figs. 1 and 2 bear the y same numerals used in Figs. 1 and 2.

In the construction illustrated in Figs. 3 and 4 the spider portion l'of the valve sleeve 62 may be apertured, if desired, and is provided with rearward projections 84 having longitudinal slots therein and receiving latching dogs 36 pivoted thereto at 8B. Two diametrically opposed sets of slotted projections Sii are preferably provided so that two dogs tit are provided positioned in diametrically opposed relation and swinging about their pivots 88 in a radial direction. The dogs 8B project rearwardly from the valve sleeve S2, that is, toward the left as viewed in Figs. 3 and 4, and at their free ends mount inwardly projecting stop pins 90 normally spaced apart as illustrated in Fig. 3. A coil spring92 bears at its opposite ends against the inner faces of the dogs 85, and its end portions encircle the pins sil. The coil spring 92 serves normally to press the dogs 8E radially. outwardly. lla-ch dog 85 has a latching shoulder 94 formed in its outer surface intermediate its ends and is also provided with a camming surface 925. The follower 'it is provided with a circumferential shoulder 98 intermediate its ends, so positioned Vthat when the forward or right-hand edge of the follower bears against the k left-hand'edge of the valve sleeve 62, thelatching shoulders 94 upon the latch members 86 Will engage the follower shoulder 93. In this way, as best seen in Fig. 3, a mechanical interlock is provided between the valve sleeve 62 and the follower '58, the same being normally maintained by the pressure of the spring 92 acting against the latch members 8E.

In the operation of this device, when the prese sure within the coal-breaking cartridge reaches a Value which enables the plunger 68 to shear the shear member 58 and thereby bodily move the sleeve valve 62 toward vthe right to the open posi tion illustrated in Fig. 4, the initial movement of the pressure responsivesleeve 62 will carry with it the follower l. The follower 78 is'of pressure balanced construction, that is, it has v'clearance within the tube I8 permitting equal gas pres'- sure to act against all surfaces thereof and avoid ing any tendency of the contained gas pressure to urge the sleeve in any direction. In other words, the sleeve 18 is balanced and the pressure in the device has no tendency to move it. The

. latching shoulders 94, 98 upon the latch elements 86 and the follower 78, respectively, are somewhat beveled or angularly displaced with relation 'to the axis of the sleeve I8 and are thus capable of providing a camming action. This camming action results in the release of the latch when 'the enlarged end 8B of the follower 'i8 engages the shoulder i6 of the outlet tube portion I8'of the coal-breaking cartridge. In other words, the camming action serves to swing the latching members 86 inwardly against the actionof the spring 92, thus disengaging the latch members from the follower 'i8 and permitting continued movement of the valve sleeve toward the right to the fully open position illustrated in Fig. 4.

After'the charge of gas has been discharged from the coal-break cartridge by the movement of the parts to the position illustrated in Fig. 4 with the resultant reduction in pressure in the cartridge to a value which exerts a force less than the force exerted toward the left bythe spring lil, the spring 'l comes into play to move the sleeve valve 62 toward the left to resume a closed or Vsealing position. The spring is of suffi'- cient force and strength to move the follower'l to the position illustrated in Fig. 2 along with the sleeve valve 62, and also causes the latchlng dogs 86 to re-assume a latching position. The cam surfaces 96 upon the latching dogs facilitate the return of the parts toward latching position and in particular cams the latch 'dogs 86 inwardly to ride over the shoulders formed in the interior of the follower sleeve as the parts vare moved by the spring 'l0 to the left from the position illus-- trated in Fig. 4 to the position illustrated in Fig. 8.

It will be understood that the construction of the device illustrated in Figs. 3 and 4 constitutes trated in Figs. and 6. InV this embodiment of Athe invention, parts similar to the parts shown in the embodiments of Figs. 1 to 4, inclusive, bear the same numbers. The device illustrated in Figs. 5 and 6 is primarily characterized by a magnetic coupling between the follower and the valve sleeve. Thus as illustrated, the follower sleeve 18 at its forward end carries an annular strong permanent magnet |00 whose force or strength is normally sufficient to cause it to follow movement of the valve sleeve S2 from Fig. 5 position toward Fig. 6 position through the full scope of movement permitted by the longitudinal clearance between the shoulder defined by the part 8@ of the sleeve 18 and the shoulder l@ formed in the interior of the outlet tube portion I8 of the coal-breaker Acart-ridge. This device operates similarly to the devices previously mentioned. More particularly, this device is characterized by normal magnetic coupling between the follower 18 and the sleeve valve 62 suoli that the follower 'i8 will assume a protective position within the annular resilient sealing member 28 as the pressure responsive movement of the sleeve B2 toward open position commences. The movement of the follower continues until it strikes the shoulder it and thereupon the pressure responsive movement of the valve sleeve continues, thus permitting the sleeve valve to separate from the follower and to expose the outlet poits 24.

It will be understood that changes in the construction oi the device may be made within the scopeof the iappended claims without departingfrom the spirit of the invention.

I claim:

l. A coalbreaker comprising a hollow body adapted to contain gas at high pressure and having a lateral discharge opening intermediate its ends, a sleeve valve axially slidable in said body between open and closed positionsrelative i to said opening, a pair of annular resilient sealing members circumferentially carried by said body at opposite sides of said discharge opening and engaged by opposite ends .of said sleeve valve when in closed position, a sleeve follower axially slidable in said body, means mechanically coupling said valve and follower whereby said foi`- lower moves to protective engagement with one of,V said sealing members as said valve shifts axially from closed position toward open position clear of said sealing member, and a stop limiting axial movement of said follower in a position clear of said discharge opening.

2. A coalbreaker comprising a hollow body adapted to contain gas at high pressure and having a lateral discharge opening spaced from one end, a p-air of spaced circumferential seals, said discharge opening being positioned between said seals, a pressure actuated sleeve valve shiftable axially between a closed position spanning said opening and engaging said seals and.

.an open position clear of one seal and said a pressure-balanced sleeve follower able axially between a closed position spanning said opening and engaging said seals and an open position clear of one seal and said opening, a pressure-balanced sleeve follower slidable axially in said body between a position engaging said valve when closed and a position clear of said opening and engaging said one seal, means releasably connecting said valve and follower, said Valve pulling said follower therewith as it moves toward open position, and a stop limiting movement of said follower at said last named position.

4. A coalbreaker comprising a hollow body adapted to contain gas at high pressure and having a lateral discharge opening intermediate its ends, a sleeve valve axially slidable in said body between open and closed positions relative to said opening, a pair of annular resilient sealing members circumferentially carried by said body at opposite sides of said discharge opening and engaged by opposite ends of said sleeve valve when in closed position, a sleeve follower axially slidable in said body, means mechanically coupling said valve and follower whereby said follower moves to protective engagement with one of said sealing members as said valve shifts axially from closed position toward open position clear of said sealing member, and a stop limiting axiai movement of said follower in a position clear of said discharge opening, said mechanical coupling means constituting a spring pressing said follower against said valve.

5. A coalbreaker comprising a hollow body adapted to contain gas at high pressure and having a lateral discharge opening intermediate its ends, a sleeve valve axially slidable in said body between open and closed positions relative to said opening, a pair of annular resilient sealing members circumferentially carried by said body at opposite sides of said discharge opening and engaged by opposite ends of said sleeve valve when in closed position, a sleeve follower axially slidable in said body, means mechanically coupling said valve and follower whereby said follower moves to protective engagement with one of said sealing members as said valve shifts axially from closed position toward open position clear of said sealing member, and a stop limiting axial movement of said follower in a position clear of said discharge opening, said mechanical coupling means constituting a inagnet carried by one of said sleeve members at the end thereof adjacent the other sleeve member.

6. A coalbreaker comprising a hollow body adapted to contain gas at high pressure and having a lateral discharge opening intermediate its ends, a sleeve valve axially slidable in said bo`dy between open and closed positions relative to said opening, a pair of annular resilient sealing members circumferentially carried by said body at opposite sides of said discharge opening and engaged by opposite ends of said sleeve valve when in closed position, a sleeve follower axially slidable in said body, means mechanically coupling said valve and follower whereby said follower moves to protective engagement with one of said sealing members as said valve shifts axially from closed position toward open position clear of said follower in a position clear of said discharge opening, said mechanical coupling means constituting a latch having interengaging parts carried by said sleeve members and normally spring Yiressed to locking relation.

7. A. coalbreaker comprising a hollow body adapted to contain gas at high pressure and having a lateral discharge opening intermediate its ends, a sleeve valve axially slidable in said body between open and closed positions relative to said opening, a pair of annular resilient sealing members circumferentially carried by said body at opposite sides of said discharge opening and engaged by opposite ends of said sleeve valve when in closed position, a sleeve follower axially slidable in said body, means mechanically coupling said valve and follower whereby said follower moves to protective engagement with one of said sealing members as said valve shifts axially from closed position toward open position clear of said sealing member, and a stop limiting axial movement of said follower in a position clear of said discharge opening, said mechanical coupling means constituting a latch carried by one sleeve member, a shoulder on the other sleeve member, and spring pressing said latch to interlocking engagement with said shoulder.

8. A coalbreaker comprising an elongated cartridge adapted to contain a charge of gas at high pressure and having a lateral discharge port adjacent to one end, a pressure actuated sleeve valve shiftable longitudinally in saidcartridge and adapted to span said port, a shear member carried by said cartridge and normally resisting movement of said valve to open position, a seal carried by said body adjacent to said discharge opening, said sleeve valve engaging said seal in its closed position and shifting clear of said seal upon movement to open position. a pressurebalanced follower shiftable in said cartridge, a stop limiting movement of said follower toward said port, and a releasable mechanical coupling between said sleeve valve and follower whereby said follower moves with said valve upon failure of said shear member and until said sleeve follower engages said stop.

9. A coalbreaker comprising an elongated cartridge adapted to contain a charge of gas at high pressure and having a lateral discharge port adjacent to one end, a pressure actuated sleeve valve shiftable longitudinally in said cartridge and adapted to span said port, a shear member carried by said cartridge and normally resisting movement of said valve to open position. a seal carried by said body adjacent to said discharge opening, said sleeve valve engaging said seal in its closed position and shifting clear of said seal upon movement to open position, a pressure-balanced follower shiftable in said cartridge, a stop limiting movement of said follower toward said port, and a spring pressing said follower against said sleeve valve and toward said port and said stop.

l0. A coalbreaker comprising an elongated cartridge adapted to contain a charge of gas at high pressure and having a lateral discharge port adjacent to one end, a pressure actuated sleeve valve shiftable longitudinally in said cartridge and adapted to span said port, a shear member carried by said cartridge and normally resisting movement of said valve to open position, a seal carried by said body adjacent to said discharge opening, said sleeve valve engaging said seal in its closed position and shifting clear of said seal upon movement to open position, a pressure balanced follower shiftable in said cartridge, a stop limiting movement of said follower toward said port, and a permanent magnet carried on one of said valve and follower members, the other of said valve and follower members being formed of magnetic material.

11. A coalbreaker comprising an elongated cartridge adapted to contain a charge of gas at high pressure and having a lateral discharge port adjacent to one end, a pressure actuated sleeve valve shiftable longitudinally in said cartridge and adapted to span said port, a shear member carried by said cartridge and normally resisting movement of said valve to open position, a seal carried by said body adjacent to said discharge opening, said sleeve valve engaging said seal in its closed position and shifting clear of said seal upon movement to open position, a pressure balanced follower shiftable in said cartridge, a stop limiting movement of said follower toward said port, one of said valve and follower members carrying a latch and the other having a part releasably interlocked with said latch, and a spring pressing said latch toward interlocking position.

EDWARD C. FILSTRUP.

No references cited. 

